Conventionally, to supply water to buildings such as factories, offices and respective households, water pipes through which water taken in from rivers or the like flows are buried underground.
When a building is newly built, there may be a case where, to supply water to a water area in the building, a construction work is performed so as to mount a snap tap for diverting water from an existing water pipe on the water pipe.
In such a case, a water diverting port is formed by drilling a peripheral wall of the water pipe with a drilling machine equipped with a drill, and a metal sleeve or a snap tap integrally formed with such a metal sleeve is mounted on a periphery of the water diverting port together with a rubber packing so that water can be taken out from the water pipe in a diverting manner while preventing leakage of water from the water diverting port.
Particularly, recently, in locking and fixing a metal sleeve or a sleeve portion which is integrally formed with fc also simply referred to as “metal sleeve”) to a water diverting port, there has been proposed a method where an opening portion formed at one end of the metal sleeve is made to project from the inside of the water diverting port of the water pipe, and a distal end portion of the opening of the metal sleeve which projects into the inside of the water pipe is bent by a diameter enlarging head mounted on a distal end of a main shaft of a jig inserted into the inside of the metal sleeve, a diameter enlarging roller mounted on the diameter enlarging head obliquely and the like such that the distal end portion of the opening of the metal sleeve is folded back on an outer periphery of the metal sleeve, and the distal end portion of the opening of the metal sleeve is caulked to the water diverting port of the water pipe.
In this manner, to enable mounting of the snap tap while ensuring watertight connection between the water pipe and the mounting portion of the snap tap, there has been known the use of the snap tap mounting jig which is, as described above, constituted of the diameter enlarging head mounted on the distal end of the main shaft and the diameter enlarging roller mounted on the diameter enlarging head or the like obliquely.
As described in detail in patent literature 1, for example, with respect to the manner of operating the jig, the diameter enlarging roller having a Japanese-hand-drum shape and mounted on the diameter enlarging head formed on the distal end of the main shaft obliquely is brought into contact with the peripheral edge portion of the opening of the metal sleeve while manually adjusting the elevation or lowering of the main shaft and, subsequently, the peripheral edge portion of the opening of the metal sleeve is bent by the diameter enlarging roller arranged on the distal end of the main shaft such that the peripheral edge portion is folded back to the outside by rotating the main shaft and, thereafter, the peripheral portion of the opening of the metal sleeve is engaged by caulking to the peripheral edge of the water diverting port formed by drilling in the peripheral wall of the water pipe thus making the snap tap engaged and fixed to the water diverting port and performing sealing of the water diverting port with certainty.
In this case, the structure is adopted where the metal part is caulked to the water diverting port of the water pipe. Accordingly, when a pipe wall thickness of the water pipe differs or a size of the water diverting port differs, it is necessary to communicably connect the snap tap to the water diverting port with certainty in a state where a complete sealing function is acquired corresponding to a change in such a situation. To this end, it is necessary to bend and caulk a diameter-enlarged end edge portion of the metal sleeve to the water diverting port of the water pipe with certainty.